Produced in Japan from 1974-1980, it was first broadcast in the United States in 1979. Significantly, it was the first popular English-translated anime that had an over-arching plot and storyline that required the episodes to be shown in order. Even while being toned down a bit by editing, it also dealt with much more mature themes than any other productions being aimed at the same target audience at the time. As a result, it paved the way for the introduction and popularity of future arc-based, plot-driven anime translations.